| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery having high capacity, high working voltage, and excellent load characteristics. <P>SOLUTION: The lithium ion secondary battery has a positive electrode containing as an active material LiCoO<SB>2</SB>(A) and a compound (B) represented by general formula, Li<SB>x</SB>Ni<SB>y</SB>Co<SB>z</SB>M<SB>(1-y-z)</SB>(wherein, 0.5≤x≤1.2, 0.9≤y+z<1, Y>0, z>0, M is at least one element selected from Al, Mn, Fe, Mg, Si, Ti, Zn, Mo, V, Sr, Sn, Sb, W, Ta, Nb, Ge, and Ba) in a mass ratio of (B)/(A)=0.04 to 0.8, having a positive mix layer having a density of 3.7 g/cm<SP>3</SP>. <P>COPYRIGHT: (C)2007,JPO&INPIT |
